Ducman82

Building an S3 Motor. Looking to use a set of Colin's cams , but I am having a brain meltdown trying to figure out what valve springs to use. .437 is the cams lift. I have not heard back from some spring makers with regards to what will fit, or what needs to be done.

Some say machine the head, use S4 springs. Other say u can't do that.

Ugh. I looking for what others have done on the S3 platform.

atb

I have a complete set, never opened, never used 944S 87-'88 16V M44.40: 944.105.907.01 valve springs which I believe are a drop in for the S3 (someone please correct me if I'm mistaken). These were the old school valve spring of choice for high lift cams in a 32v motor. Believe both the DEVEK strokers running the b1 cams and Mark Anderson's stroker ran these at one time or another. 928 intl used to list them on their website, not sure if they still do. Don't recall what I paid, but would let them go for a discounted price. Would be good if Colin could confirm that they would work on his cams.

jcb928

list now is $37.00 each

http://www.jimellisporscheparts.com/...410590701.html

Ducman82

PM sent ATB> i hope to find out, but i think you are right.

KenRudd

OBehave

After reading the"carnage" thread which included valve springs and Colin's cams, I wpould call Greg Brown and take his advise on the matter.
Just mu .02 cents.

Ducman82

Sent him an email. Waiting to hear back.

Ducman82

Check an email for a week or two ago. He said 944S2 springs will work up to .425 lift.... Not quite enough.......

OBehave

--------------------------------------------------------------------------------
Someone just told me that I was too verbose and made it too complex to understand.

Gee, that's uncommon, for me!

Simplified Version:

Aftermarket springs are generally ****. These particular spring have spring pressures that are way too high (my humble opinion).....even if they didn't break.

New cams should always have new lifters. Use the lightweight German made VW lifters.....they are cheaper than the stock lifter.

For cams up to .425" lift, use a 944S2 spring with a 928 S3 spring seat.

For cams with more than .425" lift, use the Porsche racing spring, with the S3 spring seat.

Yes, either spring will cost you more than the cams did......but fixing broken parts and fixing damage will cost more than the springs (and lifters) ever could.

Do it once. Do it right. Drive it.
__________________
greg brown




copied it over here for future search.

Ducman82

Anyone know what the part number for the racing spring is?

ptuomov

Is that for S4 or S3 or both? Vaguely recall from the WSM that there are a lot of differences between S4 and S3 components that determine the valve spring installed height.

Ducman82

i was under the impression that was for the S4 motor. thats why i was searching for S3 specific info..

GregBBRD

Obviously, I know the part number. I spent an entire week measuring an recording valve spring pressures from about 30 different springs....from 5-6 different sources.

Porsche racing is a very "strange" place. Very German and very controlled.

They make their pieces for use in the Cup Cars....nothing else. They calculate how many replacement pieces they are going to need and build that many pieces. People started buying the carbon fiber front bumper insert pieces and installing them on street cars. People started buying the racing limited slips and started installing them in street cars.

Now, in order to get pieces, you have to give them the chassis number for which Cup Car the pieces are going to be used in....

A bunch of 928 geeks calling Porsche Motor Sports, looking for valve springs that are going to fit in their 928 engine.....isn't going to even remotely work.

Sorry, not going to add to that problem by giving you a part number for something you can't possibly buy.....and potentially screw it up, for me.

The "racing spring" I use cost $54.00 each.....depending on the "Euro". I use them when I have lifts over .425", which is what I determined to be the upper "limit" for the 944 spring. There's another beautiful racing spring which has custom trimmed tails, is made from special wire, and is polished. About $145.00 each. has about 15% more pressure than the "economy" racing spring.

Ducman82

completely understand that for sure. Thanks Greg. if i read everything correctly, then with the S3 bottom perch, 944S springs should work in S3 heads. ill give them a shot. Lots and Lots of variable to consider when checking spring specs out, made my brain hurt. i dont mind spending the money, just did not understand what would work with what.

GregBBRD

I'm hoping that is not what I said....or gave the illusion of saying.

I've never fit a higher lift set of cams into an S3 engine....so although I can't tell you, for sure, what is going to happen, follow this logic:

The valve springs and retainers are the same in both an S3 and an S4. The spring seat, on the bottom, is thinner on the S3 than the S4, which means that there is less room from the retainer to the aluminum casting in an S3 head, not more!

I use the S3 spring seat in the S4 heads to get more room to allow the 944 spring to work.

It would logically seem that fitting the same spring in the S3 head (less available room) is going to be tough/impossible.